Truck.



G. L. MASON.

TRUCK.

APPLICATION FILED MAY 21. 1913.

INVENTOR. Georye L. M3011. BY {4 9 ATTORNEY Patented Mar. 21, 1916:

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Patented Mar. 21, 1916.

2 SHEETS-SHEET 2.

Geozye LMa-sazz Za 9 d A TTORNE Y.

6. L. MASON.

TRUCK. APPLICATION FILED MAY 21, I913.

WITNESSES: 1/45? fit? UNITED STATES PATENT OFFICE.

GEORGE L. MASON, OF WAREHOUSE POINT, CONNECTICUT, ASSIGNOR TO THE GEORGE P. CLARK COMPANY, OF WINDSOR LOCKS, CONNECTICUT, A CORPORATION OF CON- NECTICUT.

TRUCK.

Specification of Letters Patent. 'Patented Man 21 1910 Applic tion filed May 21, 1913. Serial No. 768,912.

.or four wheeled truck provided with a base and a platform capable of being-raised or elevated away from the base in order that the truck may be wheeled underneath a load of paper, brick, or what not, upon a suitable support, the platform elevated, picking up the load, andthelnadthflraylgeeled away.

Trucks of this character heretoforemanw factured, in so far asI have been aware, generally comprise a steering handle directly associated with the front wheeler wheels which are mounted upon the same axle and mechanism whereby, When-the handle is pulled down, the platform.may be elevated, but these devices have all been objectionable for the reason that, before the platform can be elevated, it has been necessary to point the handle substantially straight ahead.

In a truck constructed, on the other hand, according to my invention, the steering handie is preferably indirectly connected with the two front wheels which are all caster form and instead of being mounted upon the.

same axle, are turned on their vertical pivots in the lower platformor base portion of the truck. Moreover, the elevatingmechanisms of in new and improved truck have beelrso,

constructed and arranged that it is entirely immaterial in what direction the handle happens to be pointing at'the time it is depressed for raising the platform; the platform going up exactlvas well whatever the position of the handle.

Trucks constructed according to the old prai-tice, in so far as I am aware, have furthermore been objectionable andfaulty on mechanical principle, for the reason that the elevating devices for the platform have been so arranged that they take their movement correspondingthroughout to the' depressing movement of the handle. I

Ell invention, on the other hand, includes a construction and arrangement whereby the elevating devices go into action slowly, hav- -useful and novel.

ing a slight, and almost imperceptible, movement to correspond with the beginning of the depressing movement of the handle, which movement increases thereafter, as the handle is further depressed, thereby giving an easy start. This makes the entire operation of the device correct on mechanical theory and much more eflicient in practical operation.

Besides these features which]: have been at pains to particularly point out as comprising important parts of my invention and which I consider both useful and broadly new, I desire at this point to call attention to another feature wherein my truck is both This relates to an automatic self-locking arrangement whereby the platform, by the construction and arrangement-pf the elevating devices themselves as distinguished from the operating mechanism therefor, is locked at closely consequent successive points throughout its entire lifting movement, the lift of the truck thereby resolving itself into a series of short lifts after each one of which the truck is locked in position and cannot be depressed by the load. This me mechanism operates in precisely the same manner when the truck is to be depressed, the lifting devices as they areoperated to lower the truck automatically look ing after each slight movement in a downward direction. This I consider broadly new.

Another important feature of the invention comprises the arrangement whereby I make use of two superposed and mutually engaging cams which means (from a practical standpoint) that I have been enabled to double the lift of the platform without materially increasing the minimum height of the platform from the floor. vantage inherent to the arrangement resides in thefact that the platform, while being raised has no longitudinal movement whatever relative to the lower platform but lifts by straight vertical lift as distinguished from the sliding lift of the trucks'hcretofore made. V

Another feature of my mvention resldes in the construction and'arrangement whereby without the use of pawl-and-ratchet" mechanisms or their equivalents the handle may, if desired, be operated successively. a

. substantially vertical position, thus giving anv other mechanism requiring attention on the part of the operator, butflows auto?- him a purchase notpossible were it neces' .sarv for him. to raise the platform by -following through one depressing movement of the handle from a substantially vertical to a substantially horizontal position., The advantage, moreover, is attained, as Said above, without the employment of pawl-andratchet mechanisms or their equivalent or matically from the nature of the lifting devices themselves. This I consider broadly new. a

All these features which I have hereinabove briefly alluded to will be found fully detailed and emphasized'in the accompany-' ing specification. w i

In the drawings-Figure l is' a top,1plan view of my improved truck. Fig. 2 -is aside view. F'g. 3 is a longitudinal cross-section taken on the medial line of Fig. 1. .Fig. 4 is a cross-section taken on the line 44 1. Fig. 5 is a cross-section taken on line 5'-5 of Fig. lg-and Fig. 6 is adetail view o'n a larger scale'illustrating the cam liftingv device forming an important feature of my' I invention.

.My truck comprises a frame and a platform A and '13, frame A being. supported upon the rear wheelsa and having swiveled front wheels a. Platform B is adapted by mechanism hereinafter to be described to be raised from frame A'and away from the same. Frame A carries brackets A by which it is-supported from'the' axle of'the rear wheels of the truck in an old and fa- ,fniliar manner. .At the front end of'frame A and integral therewith is a vertical bearlowerend a. cross-bar d adaptedto enterIin and'engagethe slots ofthe toothed wheels d. Between, these toothed wheeled and rigid therewith is a pinion d" forl coiipera tionwith a cylindrical rack, and carried in the bearing d is a cylindrical rack 'd} '(of th'zl iiatuiie ofa screw but without pitch) as ing D carrying a sleeve memb'er d provided vyith'a pair of arms d at itsupper end and a downwardly-projecting integral segmental boss'd at its lower end. Between the arms '-;is mounted a shaft (1! and on this shaft is,v

inturnfmounted a pair of toothed wheels dl Between the members d and the wheels df and upon the shaft 01 iscarried upon bearings the U-shaped member d carrying e vpipe handle d is a spring-pressed plunger (l9 carrying at its the pipe-handle. d etipippedf-with a, crossrod d}. Mounted in t Clearly 'E- ISuPPOrtedon a pair of brackets E depending from 'the' frame A'is a 'gear-wheel e in mesh withtthe. cylindrical kd andl also with a' of Fig..

e? carried on a shaft e mounted in brackets E at opposite sides of frame A. This shaft e carries a pair of-cams e, and upon shafts a carried by depending lugs E and E of platform B are corresponding cams e and e". The cams are shown in detail in Fig. 6. Each cam is provided with a flange e corresponding to the contour of the cam, as clearly shown in Fig. 6, and between the two -shafts e and e are mounted correspondworthy of a detailed description. The cams eat-are provided with a series of circular bosses e while the cams e are provided with a corresponding series of circular recesses c. Between these bosses e are flat portions e, and between thecircular recesses'e are flat portions e, these portions lying in the'tangential plane of the cam at the points at which they occur. The result of this construction is that, as the cam e is rotated, it correspondingly rotates the cam e and as soon as any one projection e passes the common vertical line of centers of the shafts e? and c, this boss automatically goes over to the position shown in Fig. 6, in which the two cams are shown as supported upon two bosses, in engagement with their corresponding recesses, the fiat por tions between the bosses and the recesses being parallel and traversing the common vertical line of centers of the two shafts e and a In other words, the action throughout the entire revolving contact of the two cams resolves itself into a succession of toggle motions, each projection t lifting the cam e and then, as it asses center, allowing the cam e?" to go bad k slowly to a locked position. place whatever the direction in which these camsare rotated. It will be thus clearly seen that, by this arrangement, the lift of the platform has been made self-locking not onlyin itsextreme positions but at many positions intermediate its extreme positions and that this has been done not by the probut-by the very nature and construction of "the lifting devices themselves.

Upon the shaft a hereinabove alluded to,

is a pinion f engaged within a horizontal rack f (Fig.4),which rackis; confined to the pinion f by an anti-friction roller f ca'rried'on a depending web f from frame A. The rack f engages at its other end a pinion f secured to the rear aide f of the Exactly the same action takes truck. This reaf axle is supported mi bearings f formed integrally with the frame A and carries wheels a. The rack f is held in contact with pinion f by a roller 7" carried on a web depending from frame A, as clearly shown on Fig. Depending from platform B are a pair of brackets 7 and g supporting a shaft which shaft. carries cams g cooperating with cams 5 upon shaft f precisely as the cams (1* cooperate with the cams e in the mechanism heretofore described. These cams and are provided also with a pair of slotted bars carrying pins precisely as illustrated in Fig. (3 and described in connection with the mechanism at the front end ofthe truck. Depending from the platform B are brackets B at either side of the rear ends thereof and brackets E at either side of the front there of. These brackets carry rollers I)" at the rear end and Z1 at the front end, which rollers are engaged in slots in the brackets A and E on frame A, in order to prevent the upper platform B from having longitudinal movement with respect to the lower frame A. Upon opposite sides of the front of the lower frame A are mounted, by a wellknown ball-bearing support, as shown in Fig. 2, casters 'H and H carrying the front wheels at of the truck. These casters are connected through the intermediary of lugs h with radius rods h, which rods are, in turn, connected at their lower ends to depending circular boss 11 on the member (7. By this means, the truck may be steered by its handle d, radial movement of the handle (1 in a horizontal direction being eoinniunicated through the bearing (Z to the radius rods h and thus to the individual casters on the front of the frame.

The operation of my new truck is as follows :-By operating the rod ll by means of its plunger, the cross-rod (Z can be en- 'gaged with anv one of the slots in the wheels 11 and the pinion rl. rigid therewith, thereby revolved. This pinion. whatever the position of the handle (1", engages the cylindrical rack which, in turn, operates the pinion e to in turn rotate the pinion :1 upon the shaft e. The rotation of this shaft revolves cams a, which being provided with the projections 0" taking into the recesses w of the corresponding cams e", roll these cams. The result of this operation is to lift the platform by a series of steps, the lifting process being reduced to what is tantamount to a series of toggle actions and being antomatically self-locked at many points throughout its duration. From an inspection of Fig. 6, it will be noted that the radial distance from the periphery of the cams c and 1:" from their supporting shafts does not. uniformly increase for equal angular inore :uents of rotation of the shafts. For eunal angular movements of the shaft the CFC-- ment of increase of this radial distance br comes greater as the cams are turned from the position shown in Fig. in other words. if the cams are turned through an angle of 30 degrees from the position shown in Fig. e a certain increment of separation of the shafts r and c is obtain d and on a subsequent movement of lid degrees another increm nt of separation is obtained. The latter incren'zenl is not. however. equal to the first but somewhat greater and each of such iiirrezncnts gradually increases over the former inc ements The li acii n is, thus, slow at the beginning and thereafter increases as the enlarged portions of the cams are brought to bear upon ouch other. which makes for-aneasy lift asexplaiued here inabove. Exactly the same elevating process, brought about through the same niechanisni, is carried on meanwhile at the rear end of the truck through the intermediary of the rack f, the pinion f, shaft 7, and earns g and, The pins e cooperate with the flanges 0", thereby preventing (at both the front and rear ends of the truck) the top platform ll from being lifted off the frame A, while the rollers 0 and 7c", being confined in vertical slots in the brackets A and E, prevent longitudinal movement of the platform B.

It is to be particularly noted that the (,IOSS-bfl r may at any time be shifted from one pair of alined slots in the wheels (1 to another, thus enabling the operator to raise the platform by a ser es of short pumping operations in which the handle plays in the some small ar This in an important advantage where heavy loads are to be raised.

Having now described my invention, but recognizing that it is not to be confined to l precise structure l have chosen by Wlllt'l'l to illustrate it. but that, on the other hand, many modifications and mrtures from this precise structure are possi e within the scope of the invention which more truly bounded and defined by the claims hereto appended, .l' clainn I. In a lifting truck, abase. a swivel mounted in said base. a cylindrical rack car- "led by the swivel. a steering handle carried by the swivel. and means associated with the handle for the operation of the rack.

2. Tu a device of the class flPSCl'lllkil. ioeluding a frame. a movable platform, a swivel on the frame, a columns; raclv raw ried by the swiveLa pinion mounted in the swivel, a. steering handle connect d to the swiveLand means associated with the haudie indepeiulently mowible thereon 'at the will of the operator and arranged to operate said pinion. together with means for elevat ing the platfm'm adapted to be operated by the rack.

3. lfn an elevating truck. including a mowable platl" 1n'i:='=, a. frame and means to elevate thc pln-ii'orn'i from thc frame, a swivel mounted in thc latter, a stccring handlc conncctcd to the swivel, Li vertically movable transmitting incmhcr mounted in said ci. a dcvicc to clcvutc thc snmc, opera tire connections bctwccn said Il1Qli1l)( and szshl i tform Howling means. and mvnns :issoriatcd with tho ring handle operable al this will of tho opcru or to :mtmitc said dcricc, whcrcb s2: ed pinit'orm may be clcvntcd.

A. lilting; trml; omprising. in combr mnion. 2i ilrzinic 11 neon iilc platform, a plurality of can rotnluhly mounted on the twin, 2: plnrnlirv oi cums rotntably mounted on the platform and c igng'cziblo with the first named cams, whereby a series of lift inc: dc ices arrange ll in pairs is provided, and men opcruhic to turn onc com of each pair. onc coin of curb pii'ir having its pcriph rim-l with n scrics in spnccd rcccsscs her cmn ot' cnrh pair having its pcriplr of spuvcd projccrcccsscs, whereby b mtatcd b the arranged so that cry 2 in? ol formcd with a scrios enim icnblrn said onscan: Hi curl; pwir may other, all mnstrm l and nornml y two pro ections of one cmn cn c h "n on two rrrcsscn oi (hr l'll iiiillyf ams on op po c shins ot' lln': linc of ccntcrs of a pair ot m and. so that its any i in e tion with its :r rccc rror scs said no of comers. thi -r ni rs m lurch-ii ihrthcr :apnrt oi" scll' lurking increio'lo n srrws i'rnch. comprising. in combi- 'livclr(l frame. :1 niornhlc plat- ?orro. a plurality ct cums cur-rind by thc ironic. n plurnl ry ct nuns ('fil'iifll by llli, pluiform and i'flf'flgffiilll'r with tho first nnmcd cams. whorm'iy 2i scrir-i: of lifting dc viccs arranged in. pair is providod. a: stem ing: lmndlc monntcd on the trims, and means opc tillc from said lmndlc to turn our ("aim ol mch rail: om run: of Pillil pair having in yo hcry fornml with scrics of spaced zw-cs-scw. tho. tllit)! min: of ach pair having its pcrigihcrr forsnm! with a I li'S oi spaced proi ",tions cngnncni l in mid rcccsscs, ml; ,b mm of curb pnir 1112 bc rotntcd by." tlw ther. all lIh-(tfll lt and an" ramgcd so that nornniliy two projections of onc cnni cngngr with two rcccs r-s of tho limb iog can: on oppe'isirc sides oi the line of ccntors oi n nir of (:UHS and so that {is my proiccion niih its inning rccc: crosses said iinr oi ccnicrs, tho said ccntcrs are l'orccd liar-thornpnrt than innncdinti'ily before or ill t 'i snvb positioning, whcrcby the lifting motion is rcsolrcd into :i scrics of self locking; incromcnlis.

6. A lifting truck, comprising, in combi-- nation. a base portion. a lifting; platform, a steering hnndlc swivclcd in the base portion, lifting dcvircs arranged between the platform and base portion, each device comprisng a pair of separate but mutually engaged rotatable members, operative connections belIWtkH said devices and said handle. whereby upon depression of the latter the lifting devices may be :rtimted to lift the platform, mic member of (lltll pair having its periph cry formal with a series of spaced recesses, the other member of each pair having its periplwry formcd with a series of spaced projcctions cngngcublc in said recesses, whereby one member of each pair may be" rotated by the other. all constructed and arranged so that normally two projections of'one member engage with two recesses of the mating member on opposite sides of the line of centers of A pair of members and so that as any projection with its mating recess crosses said line of centers, the said centers are forced farther apart than immediately before or after such positioning, whereby the lifting motion is resolved into a series of self locking increments.

7, A lifting truck, comprising, in combination, 2: wheeled frmnc, a movable plat- "form, a swivel on the frame, a cylindrical rack carried by tho svivcl, a pinion mounted in the swivel and engaged with the rack, a steering handle connected to the swivel, means :issociatcd with the handle independently movablethcrcin atthe will of the op orator and arranged to operate said pinion, lifting devices between the frame and platform, each device comprising, a pair of separate but mutually engaged members, and incnns operable from said rack to actuate one incnibcr oi each pair, one member of each pair having its pcriphery formed with a serics of spnccd'rcccsscs, the other mcn'iber of each pair having: its pcripherv formed with a series of spaced projections enfgngeable in said rcccsscs, whereby one member of each pair may be rotntcd by the other. all con structed and arranged so that normally two projections of one member engage with two :w1 -c,'-:sc. of tho mating member on opposite sides of the line of centers of a pair of members and so that as any projection with its mating recess crosses saiddine of centers, the said ccntcrs are forced farther apart} than innnedinteiy before or after such positioning, whereby the lifting motion is resolved into series of self locking increments.

v GEORGE L. MASON. li itncsscs H. A, Boo'rii, CAROLINE WILLrs, 

